The work deals with observations on coronal musculature (position in relation to coronal groove and gonads) and morphological variation (number and position of stmctures) of Nausithoe aurea medusae reared for 82 days in the laboratory, and compares it with avaiable data for other species of the genus. A new occurrence of Nausithoe aurea is reportedfor the coast of Bahia State, Brazil